1. Field of the Invention
The present invention relates to a curve approach control device for estimating and judging the approach of a curve ahead for a vehicle based on information from a navigation system, and warning alarms and controlling deceleration and soon, and a vehicle equipped with this curve approach control device.
2. Description of Related Art
In the related art, a large number of curve approach control devices and vehicles equipped with such curve approach devices have been proposed where it is detected whether a vehicle is traveling too fast for an approaching curve using road map data and the like of the navigation system and alarms are then issued or control is exerted to decelerate.
For example, in Japanese Application Laid Open No. 4-236699, there is disclosed technology where an appropriate vehicle approach speed is calculated according to road characteristics such as the radius of curvature of the curve based on information for a curve the vehicle is approaching provided by the navigation system. When the actual vehicle speed is higher than this appropriate vehicle approach speed, the driver is notified of this and is commanded to reduce speed, or control is exerted to automatically decelerate according to this command.
However, map data for the navigation system is not usually updated with the most recent information, but is rather updated periodically. There are therefore many occasions where the road data for the navigation system and the actual shape of the road are not the same.
There is therefore a strong possibility of erroneous judgments occurring with regards to alarms for the approach of a curve and deceleration control of the vehicle that rely upon curve information from the navigation system. Such unnecessary alarms and the like not only make the driver feel uncomfortable, but also cause drivability to deteriorate.
In order to resolve the aforementioned situation it is therefore the object of the present invention to provide a curve approach control device and a vehicle equipped with this curve approach control device capable of judging when curve information supplied by the navigation system is erroneous and avoiding the outputting of unnecessary control commands before something happens.
A curve approach control device for predicting and judging the approach of a curve based on information for a curve ahead for a vehicle and outputting prescribed control commands comprises means for comparing and judging coincidence between curve information supplied by a navigation system and actual curve information based on actual vehicle behavior, and means for stopping outputting of the control commands when it is judged that the curve information from the navigation system and the actual curve information do not coincide.